The present invention relates to water fountain and more particularly to a structure of water and dust-proof control box for use in food machinery.
Conventional automatic conveyer devices have control boxes and so do food processing machinery since they are becoming more automatic. Control devices such as buttons, switches or turning knobs of the control boxes sometimes malfunction because of improper electrical contact, the problem is especially serious in the control boxes of food processing machinery because flour, water or dust can easily get in. As shown in FIGS. 1 and 2, a conventional control box mainly comprises a main box 10 and a back cover 20. The main box 10 is formed in one piece with a panel 11 at the front which is connected to four side boards 12. Holes 111 and 112 with mounting space around them are disposed on the panel 11. The mounting space of holes 111 and 112 are corresponding to a turning knob 113 and a switch 114 respectively for connecting together. The turning knob 113 and the switch 114 are connected by wires to an IC board 21 of the back cover 20. The back of the turning knob 113 is connected to a control knob 22 of the back cover 20. An elastic positioning piece 23 is disposed on the back cover 20 for mounting into a mounting hole 13 on the main box 10. The conventional control box has the following drawbacks:
1. The main box 10 is not directly connected to the IC board 21 which is connected to the back cover 20 instead, this make it more difficult to assemble.
2. Water, flour or dust can easily get into the control devices such as the turning knob 113 and the switch 114 through the holes 111 and 112, thus causing improper electric contact, short-circuit or malfunction. This problem is especially seriously and commonly found in food processing machinery.
3. Because the switch 114 and the turning knob 113 are only resting on the panel 11, this can easily depart from the main box 10 if being used very often. The connection between the control knob 22 and the turning knob 113 can also easily get loosed by turning and pressing manually.